1. Field of the Invention
This invention relates to a system for optically reproducing information stored in an optical recording medium such as an optical memory disc or card. This invention also relates to a system for optically recording information on an optical memory member.
2. Description of the Prior Art
Some optical information recording mediums deform or color in response to light. In writing information on such an optical memory, light from a source such as a laser is digitally modulated in accordance with an information signal, and this modulated light is applied to the memory with scanning process perfomed. In reproducing the information from the optical memory, light is applied to the memory with scanning process perfomed. Light reflected by the memory contains the information, which is derived via an optical detector.
Such information reproducing process includes the step of separating the incident light to the memory and the reflected light from the memory. A combination of a polarization beam splitter and a quarter-wave plate is conventionally used to separate the incident light and the reflected light.
Generally, characteristics of birefringence of an optical memory adversely affects the reproduction of information from the memory. In cases where characteristics of birefringence vary from memory to memory, accuracies of reproduced information derived through conventional systems tend to sometimes fall considerably.